The present invention relates to a vehicle drive device including an input member drivably coupled to an internal combustion engine, a rotary electric machine, an output member drivably coupled to wheels, a power transfer mechanism that drivably couples the input member, the rotary electric machine, and the output member, and a case that houses at least the power transfer mechanism.
1. Description of the Related Art
A device disclosed in Japanese Patent Application Publication No. 2000-217205 (JP 2000-217205 A) mentioned below is already known as an example of the vehicle drive device described above. In the following description of the related art, reference numerals and names used in JP 2000-217205 A are cited in parentheses as appropriate. In the device described in JP 2000-217205 A, as shown in FIG. 4 of JP 2000-217205 A, a ring gear (R) serving as an output rotary element of a power distribution device (planetary gear unit 13) is coupled so as to rotate together with a sleeve-like member (output shaft 14) via a flange-like coupling member extending in the radial direction. The sleeve-like member (14) is formed so as to encircle an input member (output shaft 12), and disposed on the engine side in the axial direction and on the radially inner side of the ring gear (R). A counter drive gear (15) serving as an output gear is formed on the outer circumferential surface of an end portion of the sleeve-like member (14) on the engine side in the axial direction.
It is necessary that a rotor (21) of a rotary electric machine (electric generator motor 16), the ring gear (R), and the output gear (15) formed on the sleeve-like member (14) should all be supported so as to be rotatable with respect to a non-rotary member such as a case, and thus are supported by a rotor bearing and an output bearing. Here, in the device described in JP 2000-217205 A, the rotor bearing is disposed between the rotor (21) of the rotary electric machine and the ring gear (R) in the axial direction, and the output bearing is disposed between the ring gear (R) and the output gear (15) in the axial direction. This allows the ring gear (R) to be rotatably supported by the case via a rotor shaft of the rotary electric machine (16) and the rotor bearing, and via the sleeve-like member (14) and the output bearing. The output bearing is disposed in contact with the outer circumferential surface of the sleeve-like member (14) with a relatively small diameter. This allows the output bearing to have a relatively small diameter, which enables a reduction in cost of the output bearing.